================================ WARNING: inconsistent lock state 6.11.0-rc5-syzkaller-00069-ga18093afa393 #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.0.0/5103 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff8880385759e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880385759e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff8880385759e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x243/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 3870 hardirqs last enabled at (3870): [] __local_bh_enable_ip+0x168/0x200 kernel/softirq.c:387 hardirqs last disabled at (3869): [] __local_bh_enable_ip+0x106/0x200 kernel/softirq.c:364 softirqs last enabled at (3710): [] __vsock_release+0x3d3/0x4a0 net/vmw_vsock/af_vsock.c:829 softirqs last disabled at (3843): [] __do_softirq kernel/softirq.c:588 [inline] softirqs last disabled at (3843): [] invoke_softirq kernel/softirq.c:428 [inline] softirqs last disabled at (3843): [] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pch->downl); lock(&pch->downl); *** DEADLOCK *** 7 locks held by syz.0.0/5103: #0: ffff8880380d81c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_release+0x81/0x12c0 drivers/tty/tty_io.c:1742 #1: ffff8880380d91c0 (&tty->legacy_mutex/1){+.+.}-{3:3}, at: __tty_hangup+0xcc/0x6c0 drivers/tty/tty_io.c:590 #2: ffff8880380d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #2: ffff8880380d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x6c/0xc0 drivers/tty/tty_ldisc.c:313 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #4: ffff88801b0df1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #4: ffff88801b0df1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: __sk_receive_skb+0x18c/0x8b0 net/core/sock.c:562 #5: ffff88801b0df258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb_one_core net/core/dev.c:5661 [inline] #5: ffff88801b0df258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb+0x2e0/0x650 net/core/dev.c:5775 #6: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #6: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #6: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #6: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x55/0xa10 drivers/net/ppp/ppp_generic.c:2304 stack backtrace: CPU: 0 UID: 0 PID: 5103 Comm: syz.0.0 Not tainted 6.11.0-rc5-syzkaller-00069-ga18093afa393 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 valid_state+0x13a/0x1c0 kernel/locking/lockdep.c:4012 mark_lock_irq+0xbb/0xc20 kernel/locking/lockdep.c:4215 mark_lock+0x223/0x350 kernel/locking/lockdep.c:4677 __lock_acquire+0xbf9/0x2040 kernel/locking/lockdep.c:5096 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1111 [inline] __sk_receive_skb+0x82b/0x8b0 net/core/sock.c:569 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2e0/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ce c8 39 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 63 fa a1 f5 65 8b 05 b4 d0 42 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000b83f960 EFLAGS: 00000206 RAX: 5a44c3ee1688c300 RBX: 1ffff92001707f30 RCX: ffffffff81703f6a RDX: dffffc0000000000 RSI: ffffffff8c0ad560 RDI: 0000000000000001 RBP: ffffc9000b83f9f0 R08: ffffffff937348e7 R09: 1ffffffff26e691c R10: dffffc0000000000 R11: fffffbfff26e691d R12: dffffc0000000000 R13: 1ffff92001707f2c R14: ffffc9000b83f980 R15: 0000000000000246 __debug_check_no_obj_freed lib/debugobjects.c:999 [inline] debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1020 slab_free_hook mm/slub.c:2219 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x10f/0x360 mm/slub.c:4594 tty_ldisc_put drivers/tty/tty_ldisc.c:184 [inline] tty_ldisc_kill+0x127/0x1a0 drivers/tty/tty_ldisc.c:614 tty_ldisc_hangup+0x3c4/0x4d0 drivers/tty/tty_ldisc.c:729 __tty_hangup+0x407/0x6c0 drivers/tty/tty_io.c:630 tty_release+0x32d/0x12c0 drivers/tty/tty_io.c:1760 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc824179ef9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffca0b121e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000013074 RCX: 00007fc824179ef9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc824317a80 R08: 0000000000000001 R09: 00007ffca0b124df R10: 00007fc823e0002c R11: 0000000000000246 R12: 00000000000130cc R13: 00007ffca0b122f0 R14: 0000000000000032 R15: ffffffffffffffff ---------------- Code disassembly (best guess): 0: 9c pushf 1: 8f 44 24 20 pop 0x20(%rsp) 5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 ce c8 39 f6 call 0xf639c8e2 14: f6 44 24 21 02 testb $0x2,0x21(%rsp) 19: 75 52 jne 0x6d 1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 63 fa a1 f5 call 0xf5a1fa92 <-- trapping instruction 2f: 65 8b 05 b4 d0 42 74 mov %gs:0x7442d0b4(%rip),%eax # 0x7442d0ea 36: 85 c0 test %eax,%eax 38: 74 43 je 0x7d 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss